Feeding behavior is significantly influenced by the sensory character of the food derived from gustatory, oropharyngeal, visceral, and olfactory stimuli. Such food stimuli determine palatability, acceptance, and intake, and contribute to "dietary obesity", which is an important etiologic factor in hypertension, cardiovascular disease, and diabetes. The goal of this research is to analyze the neural systems by which stimuli eliciting ingestion or rejection are integrated, and to determine how these systems influence the reflex sequences of oral behavior. This analysis, carried out at several levels of the nervous system, will provide a basis for understanding how the stimuli which elicit ingestion and rejection interact with metabolic variables and prior experience to control normal feeding behavior. Normal ingestion and rejection of appropriate gustatory stimuli occur in chronic decerebrate rats. This implies that the neural apparatus for the sensorimotor control of ingestion is organized in the caudal brainstem. Utilizing neuroanatomical and acute electrophysiological techniques, we will examine the organization of the interneuronal pool in the hindbrain which receives gustatory and oropharyngeal afferent information, and elicits the systematic, sequenced series of muscle contractions comprising ingestion or rejection behavior. Using the same techniques, and chronic recording as well, we will investigate the characteristics of the newly detected ventral neural pathway conveying gustatory, visceral, and oropharyngeal afferent information to the limbic forebrain. The limbic system has long been associated with the neural control of feeding behavior. Other experiments will determine the capacity of the hindbrain and forebrain to integrate gustatory information into complex feeding behavior.